Gluteal muscle fatty infiltration, fall risk, and mobility limitation in older women with urinary incontinence: a pilot study

Lower gastrocnemius muscle stiffness, derived from elastography, is an independent factor for falls in older adults

BACKGROUND AND AIMS

It is well known that components of sarcopenia (i.e., decreased muscle strength and mass) are related to falls in older adults. However, the possible effects of changes in muscle quality on falls have not been identified. This study aimed to evaluate the changes in muscle quality reflected by muscle stiffness derived from shear-wave elastography (SWE) and its association with falls in older adults.

METHODS

A total of 101 geriatric outpatients were included in the study. Assessments of physical performance, muscle strength (handgrip strength), muscle mass (muscle ultrasonography and bioelectrical impedance analysis), and muscle stiffness of the medial head of gastrocnemius (GCM) in relaxation and passive stretching were performed. The history of falls in the previous year was questioned and recorded.

RESULTS

The median (25-75 percentiles) age of participants was 73 (69-77) years, and 66.3% (n = 67) were female. According to fall history, participants were divided into non-fallers and fallers groups, and 72 (71.3%) and 29 (28.7%) participants were in each group, respectively. The median muscle stiffness of (Emean) the GCM in passive stretching was significantly lower in the fallers group (p < 0.001), and it was significantly correlated with the number of falls in the previous year (r: - 0.274, p: 0.010). In regression analyses, the Emean value of GCM in passive stretching was significantly associated with falls independent of confounders (OR: 0.944, 95% CI 0.90-0.98, p = 0.010).

DISCUSSION AND CONCLUSION

This is the first study to reveal the relationship between falls and SWE-defined lower GCM stiffness independently of muscle mass and strength.

Human skeletal muscle-specific atrophy with aging: a comprehensive review

Age-related skeletal muscle atrophy appears to be a muscle group-specific process, yet only a few specific muscles have been investigated and our understanding in this area is limited. This review provides a comprehensive summary of the available information on age-related skeletal muscle atrophy in a muscle-specific manner, nearly half of which comes from the quadriceps. Decline in muscle-specific size over ∼50 yr of aging was determined from 47 cross-sectional studies of 982 young (∼25 yr) and 1,003 old (∼75 yr) individuals and nine muscle groups: elbow extensors (-20%, -0.39%/yr), elbow flexors (-19%, -0.38%/yr), paraspinals (-24%, -0.47%/yr), psoas (-29%, -0.58%/yr), hip adductors (-13%, -0.27%/yr), hamstrings (-19%, -0.39%/yr), quadriceps (-27%, -0.53%/yr), dorsiflexors (-9%, -0.19%/yr), and triceps surae (-14%, -0.28%/yr). Muscle-specific atrophy rate was also determined for each of the subcomponent muscles in the hamstrings, quadriceps, and triceps surae. Of all the muscles included in this review, there was more than a fivefold difference between the least (-6%, -0.13%/yr, soleus) to the most (-33%, -0.66%/yr, rectus femoris) atrophying muscles. Muscle activity level, muscle fiber type, sex, and timeline of the aging process all appeared to have some influence on muscle-specific atrophy. Given the large range of muscle-specific atrophy and the large number of muscles that have not been investigated, more muscle-specific information could expand our understanding of functional deficits that develop with aging and help guide muscle-specific interventions to improve the quality of life of aging women and men.